Young children are either scared by thunder or curious about what exactly thunder is. If a child is frightened by the sound of thunder, an easy-to-understand explanation may help to alleviate his fears. For the curious child, your simple explanation will encourage further understanding and independent learning.
Tell your child thunder is the sound made by lightning. This is why you hear thunder and see lightning together during a thunderstorm.
If you are explaining thunder during a storm, have your child look up at the thunderclouds. If not, tell your child that thunderclouds are tall, dark and puffy clouds. Inside these clouds there are little particles of ice and water. When all the particles bump into each other, electricity builds up inside the cloud.
Explain to your child that lightning is really electricity. When the clouds get full of electricity from the collision of the ice and water particles, the electricity moves from the cloud to the ground below or to another cloud. This movement causes a bright jagged flash of light. This is the lightning that he sees during a storm.
Tell your child that the lightning bolts are quite hot--even hotter than the surface of the sun. The lightning is so hot that it heats up the air around it. The hot air expands, or gets bigger. Since lightening is so hot, the air expands quickly. The hot air pushes against cooler air making vibrations. These vibrations travel through the air, bouncing off of clouds and the ground until the sound reaches his ear. The big explosion of noise from these vibrations is called thunder.
Remind your child that our eyes can see light faster than our ears can hear sound. We see lightning first because light travels faster than sound, but lightning and thunder really occur together.
Encourage your child to learn more about thunder and lightning. For the child who is afraid of thunder, a story might help make thunderstorms less scary. Your library will have a variety of books on this subject, including the highly recommended "Flash, Crash, Rumble and Roar" by Franklyn M. Branley. There are many resources to help children learn more about thunder, including Cutts' "I Can Read About" series: "I Can Read About Thunder and Lightning."
Have your child count the seconds between the flash of lightning and the sound of thunder during a thunderstorm. For every second, the storm is about one mile away. As the thunderstorm gets closer, the time between the flash and the sound gets closer together. As the storm moves away, the count will be higher.